QueryAnswer is the .NET representation of an answer
from the Prolog server. The QueryAnswer is returned by
in response to a query
and contains variable bindings, errors, and success/failure
information. It also contains the variable bindings specified in
the query.
| Constructor Summary | |
|---|---|
QueryAnswer(PBTerm answer, Bindings bindings)
Creates a new QueryAnswer instance with the
specified information. |
|
| Method Summary | |
|---|---|
public PBTerm |
getValue(string variable)
Returns the value of the specified variable or null
if the variable is not bound. |
public bool |
queryFailed()
Returns true if the query failed (i.e. the Prolog
responded with 'no') and false otherwise. |
public bool |
isError()
Returns true if an error occurred while processing
the query and false otherwise. |
public string |
getError()
Returns the error reason or null if an error has not
occurred or if no error reason is known. |
public string |
toString()
Returns a string description of this answer. |
| Constructor Detail |
|---|
QueryAnswer(PBTerm answer, Bindings bindings)
QueryAnswer instance with the
specified information.
answer
- a Term value representing the Prolog responsebindings
- the variable bindings for the query to which this
is an answer| Method Detail |
|---|
public PBTerm getValue(string variable)
null
if the variable is not bound.
variable
- the name of the variableTerm or
null if the variable is not boundpublic bool queryFailed()
true if the query failed (i.e. the Prolog
responded with 'no') and false otherwise.
public bool isError()
true if an error occurred while processing
the query and false otherwise.
public string getError()
null if an error has not
occurred or if no error reason is known.
public string toString()